﻿//  Copyright 2016 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

using NtCoreLib.Native.SafeHandles;
using NtCoreLib.Utilities.Reflection;
using System;
using System.Runtime.InteropServices;

namespace NtCoreLib;

#pragma warning disable 1591
[Flags]
public enum EventAccessRights : uint
{
    [SDKName("EVENT_QUERY_STATE")]
    QueryState = 1,
    [SDKName("EVENT_MODIFY_STATE")]
    ModifyState = 2,
    [SDKName("GENERIC_READ")]
    GenericRead = GenericAccessRights.GenericRead,
    [SDKName("GENERIC_WRITE")]
    GenericWrite = GenericAccessRights.GenericWrite,
    [SDKName("GENERIC_EXECUTE")]
    GenericExecute = GenericAccessRights.GenericExecute,
    [SDKName("GENERIC_ALL")]
    GenericAll = GenericAccessRights.GenericAll,
    [SDKName("DELETE")]
    Delete = GenericAccessRights.Delete,
    [SDKName("READ_CONTROL")]
    ReadControl = GenericAccessRights.ReadControl,
    [SDKName("WRITE_DAC")]
    WriteDac = GenericAccessRights.WriteDac,
    [SDKName("WRITE_OWNER")]
    WriteOwner = GenericAccessRights.WriteOwner,
    [SDKName("SYNCHRONIZE")]
    Synchronize = GenericAccessRights.Synchronize,
    [SDKName("MAXIMUM_ALLOWED")]
    MaximumAllowed = GenericAccessRights.MaximumAllowed,
    [SDKName("ACCESS_SYSTEM_SECURITY")]
    AccessSystemSecurity = GenericAccessRights.AccessSystemSecurity
}

/// <summary>
/// Type of Event object.
/// </summary>
public enum EventType
{
    /// <summary>
    /// Manual reset event.
    /// </summary>
    NotificationEvent,
    /// <summary>
    /// Automatic reset event.
    /// </summary>
    SynchronizationEvent
}

public enum EventInformationClass
{
    EventBasicInformation
}

[StructLayout(LayoutKind.Sequential)]
public struct EventBasicInformation
{
    public EventType EventType;
    public int EventState;
}

public static partial class NtSystemCalls
{
    [DllImport("ntdll.dll")]
    public static extern NtStatus NtCreateEvent(
        out SafeKernelObjectHandle EventHandle,
        EventAccessRights DesiredAccess,
        [In] ObjectAttributes ObjectAttributes,
        EventType EventType,
        bool InitialState);

    [DllImport("ntdll.dll")]
    public static extern NtStatus NtOpenEvent(
        out SafeKernelObjectHandle EventHandle,
        EventAccessRights DesiredAccess,
        [In] ObjectAttributes ObjectAttributes);

    [DllImport("ntdll.dll")]
    public static extern NtStatus NtSetEvent(
        SafeKernelObjectHandle EventHandle,
        out int PreviousState);

    [DllImport("ntdll.dll")]
    public static extern NtStatus NtClearEvent(
        SafeKernelObjectHandle EventHandle);

    [DllImport("ntdll.dll")]
    public static extern NtStatus NtPulseEvent(
        SafeKernelObjectHandle EventHandle,
        out int PreviousState);

    [DllImport("ntdll.dll")]
    public static extern NtStatus NtQueryEvent(
        SafeKernelObjectHandle EventHandle,
        EventInformationClass EventInformationClass,
        SafeBuffer EventInformation,
        int EventInformationLength,
        out int ResultLength);
}
#pragma warning restore 1591

